Device for the conditioning and drying of cereals



Dec. 27, 1932. R 1,892,319

DEVICE FOR THE CONDITIONING AND DRYING 0F CEREALS Filed April 29. 1931[ZZUiZZO]? MM WWW Patented Dec. 27, 1932 UNITED STATES PATENT OFFICE-ERNST ROTH, OF. NIEDERUZWIL, SWITZERLAND, ASSIGNOR TO THE FIRM GEBRUDERBUHLER, OF UZWIL, SWITZERLAND I DEVICE FOR THE CONDITIONING AND DRYINGOF CEREALS Application filed April 29, 1931, Serial No. 533,818, and inGermany May '14, 1930.

Conditioning machines for cereals are either constructed as columns towhich the goods are fed from the top and withdrawn at the bottom,whereby the goods are moved through the column by virtue of the pressurearising from the weight of the goods, or as drums through which thegoods are conveyed by mechanical means.

In another known construction of a drying machine for any dry goods thatare adapted to be poured out each of the two sides of the horizontaldrying chamber are provided with an air chamber which is associated witha perforated pocket for the dried goods and between said pockets airconduits extending through the drying chamber are arranged which arealternately connected with the air chamber on one side and shut to theone on the other side and conversely, shut to the first mentioned airchamber and communicating with the latter. These air chambers arecommonly connected to a blower and to an outlet duct respectively andthe air which is discharged from the blower is adapted to be changedover so as to enable the air to pass through the goods deposited in thepockets alternately in the one or other direction.

The present invention relates to the first mentioned type of devicescomprising a vertical column. This type includes two classes, =thedevices of the one class being provided with heating means distributedalong the height of the column and acting on the slowly downwardlymovipg goods in conjunction with the air which is induced to passthrough the same. With the columns of the other class hot air alone ispassed through the goods once or several times either in dry or wetcondition. In connection with the devices of either class air is inducedto pass through the goods for the purpose of entraining the vaporscaused by the introduced heat. WVith this procedure the heated airencounters the goods to be treated in more or less dry condition andentrains the moisture contained in the same whereby the air is cooleddown and subsequently passes out of contact with the goods. Severalknown devices are constructed to this end in such manner that the air isled through conduits which are open at the bottom and at one end andextend across the column, from where the air is forced upwardly to be wthdrawn by way of another series of similar conduits. The air whenpassing through the first series of these cross conduits, by way ofwhich it enters the column, remains dry because condensation of itsresidual humidity is not yet apt to arise, but when the air reaches theoutlet conduits after having traversed the cereals and consequently wascooled down the water and dust content is precipitated, so that theseconduits become soiled and finally clogged. In order to avoid thisdrawback it has already been proposed to admit hot air to the exitconduits, i. e. additional but false air, with a view to render theoutgoing air more capable of absorbing humidity, so as to reduce theamount of condensation of the moisture content of the air in the exitconduits.

The present invention provides for keeping the exit conduits clean inthe most simple manner and so that the introduction of additional airwhich would increase the total amount of heat required for the operationof the device is dispensed with. For this purpose the device accordingto the invention comprising an air entrance passage and an air exitpassage and an intermediate treatment chamber through which extendbranch conduits for admission and educationof treatment air whichalternately communicatc with either passage is characterized by thepasssages adjoining the treatment chamber be ing commonly connected to asupply duct for hot air and an air discharge duct, the said passagesbeing provided, for example at their junction with the respective ductwith shutoff means adapted to be selectively adjusted for connectingeither passage to the air supply duct while the other is connected tothe air discharge duct,

In the drawing an embodiment of the device according to the invention isillustrated, by way of example only, in which Fig. 1 shows a sectionalelevation of the device in connection with a blower,

Fig. 2 is a fragmentary longitudinal section through the column of Fig.1, on a larger scale, and

Fig. 3 is a view similar to Fig. 2 of a modification of the column.

. The air which is discharged from the blower 1 (Fig. 1) passes throughthe air heating device 2 and enters corresponding to the adjustment ofthe flap 3 the one or other of the two air passages 4, 5 of theconditioning column, in the position illustrated the passage 4. The flap6 at the upper end of this passage is closed thus preventing the airfrom passing on and causing it to find its way across the treatmentchamber of the conditioning column via the entrance conduits 7 which areopen at the bottom. As, however, these conduits are closed at theirother end, the air passes through the goods to be treated tothe exitconduits 8 and as the latter are shut to the air passage 4 it flows tothe air passage 5 to subsequently leave the column at the top.Afterwards the air is led through the return duct 9 back to the blower.

. The flaps 3 and 6' are reversed incertain intervals, so that theaircurrent passes from the heating device 2 to the passage 5 on theright hand side of the column and from.

thence to the passage 4 on the left hand side across the cereals,whereafter it is withdrawn from the upper end of the column. The flap 10inserted in the return duct 9 is opened more or less for removing thesaturated air from the circulation. The flap 11 serves for controllingthe fresh air admission to the blower 1. H

- By changing over the air current from the left hand passage 4 to theright hand passage 5 the direction of flux in the branch conduits 7 and8 is alternately changed, so that these conduits are at one time actingas entrance conduits and at the other as exit conduits. The airarrivesat the exit conduit in cooled and highl saturated condition thuscausing" its humidity content to condense on the inner wall of the exitconduit and inducing dust and branny material to-stick to the wall.-

When afterwards the exit conduit is used as admission conduit thecondensate is assimi-v lated by the fresh air entering the conduit andthe dried dust; and bran particles drop off the wall of the conduit sothat the soiled exit conduit is automatically cleaned when it is usedas. an entrance conduit.

' In Fig. 2 the cross-section ofthe air con 1. In a device for' the'conditioning and drying of an uninterrupted stream of cereals, thecombination with a treatment chamber for the goods, of an air entrancepassage and an air exit passage adjoining said treatment chamber, branchconduits open at the bottom extending through said chamber and alnectingone of said passages with .the air supply and simultaneously the otherpassage with the air return for preventing precipitation. of moistureand impurities in the air circulation means.

2. In a device for the conditioning and drying of an uninterruptedstream of cereals, the combination with a treatment chamber for thegoods, of an air entrance passage and an air exit passage adjoining saidtreatment chamber, branch conduits-open at the bottom extending throughsaid chamber and alternately communicating at one end with either ofsaid passages for admission or eduction of air respectively, 'an airheating device connected with both of said passages at one end of saidchamber, a blower preceding said air heating device, an air returnconnected with both of said passages at the other end of said chamberand extending to the intake end of said blower, a control means includedin said air return in the vicinity of said blower for the admission offresh air to the latter, a control means included in said air return inthe vicinity of the'connection of the latter with said chamber for theremoval of saturated air, and air control means at each end of saidchamber for selectively connecting one of said passages with the airsupply and simultaneously the other passage with the air return forpreventing precipitation of moisture and impurities in the aircirculation means.

In testimony whereof I' have signed my name'to this specification.

- ERNST ROTH.

